In the past, injection molds were often left in the press and were run for very long part runs; and the mold was seldom removed from the press for storage. Today however, many manufacturers of plastic parts utilize "just-in-time" practices wherein the purchaser does not want an inventory of large quantities of plastic parts, but wants the parts to be made in smaller batches and to be delivered on an "as-needed" basis. In these past systems, the molds were continuously associated with the press so that counters on the press itself could be relied upon to provide the number of cycles of the mold and this was used to provide information relative to preventative maintenance, such as cleaning of the mold or lubricating critical surfaces. Where a number of molds are taken in and out of the press for just-in-time manufacturing to produce different parts on an as-needed basis, the press counters which count the number of cycles, can no longer be relied upon for maintenance schedules because a series of different molds is used in the press for relatively short periods of time. Currently, some records are kept as to when and how long a particular mold has been run, usually such records are kept in a computer log or in a paper maintenance record. Such computer logs or paper records may be used to schedule preventive maintenance of the mold. Sometimes such computer or paper records may not be an accurate or positive means of assuring that the proper maintenance is being scheduled for each of the various molds being used with the same or different molding presses. Obviously, without the proper maintenance of an injection mold, damage may occur and down time may also be the result.
Preventive maintenance of a mold is a much more critical issue today, particularly for just-in-time manufacturing parts on an as-needed basis. That is, with the advent of new, engineered thermoplastic materials, the molds are often run faster, hotter and must be kept cleaner than they had to be in the past. Therefore, the adequate maintenance for each mold is a much more critical issue today than in the past.